Stitch forming mechanism for sewing machines



July 7, 1936.

s. RIVIERE ET AL STITCH FORMING MECHANISM FOR SEWING MACHINES Filed Aug. 13, 1954 5Sheets-Sheet 1 July 7, 1936- A. s. RIVIER EYET AL STITCH FORMING MECHANISM FOR SEWING MACHINES Filed Aug. 13, 1934 5 Sheets-Sheet 2 July 7,1936. w A R'ME E 2,046,928

STITCH FORMING MECHANISM FOR SEWING MACHINES Filed Aug. 13, 1934 5 Sheets-Sheet 3 y 1936- A. $.IRlVIERE ET AL V STITCH FORMING MECHANISM FOR SEWINGMACHINES Filed Aug. 13, 1934 5 Sheets-Sheet 4 July 7, 1936.

A. S. RIVIERE ET AL STITCH FORMING MECHANISM FOR SEWING MACEINES Filed Aug. 15, 19 34 5 Sheets-Sheet 5 Patented Filly I, 193% amaze srrrcn roams MECHANISM ron snwme. moms Albert S. Riviere, Chicago, Harold J. Le 'Vescontc,

Western Springs, and Hans Hacklander, 'I'inley v Park, 111., asaignors to Union Special Machine Company, Chicago, III. a

note

corporation of llli- I Application August is, 1934, Serial No. 139.864 1 Claims. (Cl. 113-199 The invention relates to new and useful improvements in the stitch forming mechanism of a sewing machine,- and more particularly to the devices which cooperate with the needle beneath the work support.

An object of the invention is to provide a stitch forming mechanism wherein a thread carrying looper, a retainer and a stationary spreader cooperate in the forming of a looper thread loop and in the holding of said loop positively positioned for the needle to enter.

A further object of the invention is to provide a stitch forming mechanism of the above char and will in part acter wherein the thread carrying looper. and the retainer are mounted for oscillation in planes parallel with the line of feed, and wherein said looper moves in a direction opposite to the feed as it enters the needle thread loop.

A still further object of the invention is to provide a stitch forming mechanism of the above type wherein the looper and the retainer are mounted on shafts which are parallel with the actuating shaft beneath the work support and are positively oscillated through devices actuatd by said shaft.

A still further object of the invention is to provide a stitch forming mechanism of the above type wherein the shafts for the looper and the retainer are mounted in a frame which in turn is supported so that it may be swung about the center of the actuating shaft as an axis for positioning the looper where it will be readily accessible for threading. U

These and other objects will in part be obvious be hereinafter more fully disclosed.

In the drawings- Figure 1 is a view partly in front elevation and partly in section showing a machine embodying the 1 improvements;

Fig. 2-is' a view partly in plan and partly in section of the parts beneath the worksupport;

Fig. 3 is a vertical sectional view substantially on the line of feed through the machine;

Fig. 4 is a'viqw similar to Fig. 3 with the work support and feed omitted, and with the frame supporting the looper lowered to position said looper for threading;

Fig. 5 is a side view of the actuating mechanism for operating the looper and the spreader and showing the position of these parts when the looper and the retainer are retracted.

Fig. 6 is a sectional view through the throat plate and showing in side elevation the stationary spreaders carried thereby;

Fig. 7 isaview partlyinsection andpart1y'in-- side elevation showing the position of the stitch forming devices when the needle is at the lcvser end of its stroke;

Fig. 7a is a diagrammatic view in plan show 5 ing the position of the thread carrying looper, the needle and the thread loops with the parts as positioned in Fig. 7;

Fig. 8 is a view similar to Fig. 7, but showing the looper thread loop as seized by the retainer, to the looper as starting on its retracting stroke, and the needle as beginning its descent;

Fig. 9 is a view showing the position of the parts at the time when the point of the needle enters the looper thread looptor thread triangle; is

Fig. 9a is a view showing more or less diagrammatically and in plan the positively positioned loop for the needle to enter whenthe parts are in the position shown in Fig. 9;

Fig. 10 is a view showing the position of the go looper when the needle thread loop is stripped therefrom;

Fig. 11 is a detail transversely of the line of feed showing a slightly modified positioning of the stitch forming devices; 1 I 25 Fig. 12 is a view similar to Fig. 3, but showing a-sllghtly modified form of operating mechanism for the looper and the retainer;

Fig. 13 is a detail showing partly in side elevation and partly in section the means for so oscillating the shaft carrying the looper and for oscillating the shaft carrying the retainer;

Fig. 14 is a view similar to that shown in Fig. 9. but showing a slightly modified timing of the looper, and

Fig. 15 is a view partly in section and partly in plan showing the end of the looper. the retainer, the spreader and the needle; when the parts are positioned as in Fig. 14.

The invention is directed to an improvement .40 in the stitch forming mechanism wherein the stitches are formed by enchained thread loops. The stitch'forming mechanism includes a needle,

a thread carrying looper and a retainer which enters the looper thread loop and operates to retain and hold the same during the retracting movement ofthe looper until the needle has entered the looper thread loop. There is also a stationary spreader. which engages the strand of the looper thread .loop between the retainer and the previous stitch which holds said strand well away from the looper. It is through the cooperative action of thelooper, the retainer and the spreader that the looper thread loop is U held positively positioned for the point of the the looper thread loop is forced on to the same by the retainer, it will cause the strand of the looper thread loop contacting therewith to be deflected away from the looper, and thus the looper thread loop spread for the needle to enter.

Th looper actuating shaft and the retainer actuating shaft are both oscillated from a main actuating shaft located beneath the work support. As shown in Figures 1 to 5, both the looper shaft and the retainer shaft are actuated from a single eccentric, and as shown in Figures 12 and 13, the looper shaft is operated by one eccentric and the retainer shaft is operated by another. Said shaft carrying the looper and the shaft carrying the retainer are both mounted in bearings carried by a frame which in turn is mounted to swing about the axis of the main actuating shaft so that said frame may be shifted without disconnecting the actuating parts for the retainer or the looper, and thus the looper positioned where it is readily accessible for threading.

Referring more in detail to the drawings, the machine as illustrated includes a supporting'bed I carrying bearing standards 2 and 3 on which is mounted a work support I. Also mounted on the bed is a hollow standard 5 carrying an overhung arm 6, at the outer end of which is a needle head 1. Mounted for reciprocation in the needle head is a needle bar 8 which, as shown in the drawings, is provided with two needles 3 and III. The mechanism for reciprocating the needle bar is of, the usual construction and has not been illustrated. The main actuating shaft of the machine is indicated at ll. Said shaft is located for rotation in suitable hearings, in the standards 2 and 3 beneath the work support 4 and is driven by a belt wheel l2. The means for actuating the needle bar includes a, train of devices extending through the standard 5 and the overhanging arm 3.

The work support 4 is provided with a throat plate I3 having needle openings i4 therein through which the needles pass. The material is fed across the work support by a feed dog l5 carried by a feed bar 16 which is attached to a feed rocker H at its rear end; The feed rocker l1 has a stud l3 projecting therefrom, and fixed to said stud I8 is an arm H which is connected to a link 20. The link 20 cooperates with a crank on the end of the main actuating shaft l I. The feed bar is raised and lowered by an eccentric 2| carried by the main actuating shaft. An eccentric strap 22 cooperates with the eccentric 2| and is pivoted at 23 to an arm 23 which is carried by the feed bar l3. The feeding mechanism forms no part of the present invention, and will not be further described.

Cooperating with each needle beneath the work support is a complemental' stitch forming mechanism. The devices constituting said complemental stitch forming mechanism are similar in construction, and a description of one unit will answer for both. Cooperating with the arms 23 and 3|.

needle 3 is a thread carrying looper 2|. Said thread carrying looper 23 is fixed to a carrier 23 mounted on a shaft 21. The shank of the looper 25 is provided with a flat face and the set screw mounted in the carrier 23 clamps the shank against the face of the shaft 21. This will hold both the looper and the carrier in a fixed or setposition on the shaft. By loosening the screw, the carrier may be adjusted to different angular positions on the shaft, and the looper shank may be adjusted endwise in the carrier. This provides a very simple means for attaching the looper to the shaft so that it may be easily adjusted and properly set for cooperation with the needle.

The shaft 21 is mounted for oscillation in a supporting frame which includes two supporting arms 23 and 23. These two arms are connected at their outer ends by a cross bar 33. Both of the arms 23 and 23 are mounted on the actuating shaft ll so that they may be shifted about the axis of the shaft to different set positions. The cross bar 30 extends to the left beyond the arm 23, as viewed in Fig. 2, and is proand this looper 25a is also attached to the shaft 21. The looper 25a is secured to a carrier and to the shaft 21 in a manner similar to the looper 23 and may be independently adjusted to different set positions on the shaft.

The complemental stitch forming mechanism for the needle 3 also includes a retainer 32. The retainer 32 includes a shank portion having a fiat side. 'The shank of the retainer is mounted in a carrier 32d which in turn is mounted on the shaft 33. A set screw 32c mounted in the carrier 32d engages the shank of the retainer and forces the same against the shaft 33, and thus the retainer and the carrier are clamped to the shaft 33. The retainer may be adjusted on the shaft both radially and angularly in the same manner as described in connection with the looper 23. Cooperating with the needle I0 is a retainer 32a which is mounted in a similar manner on the shaft 33 and is independently adjustable thereon. The shaft 33 carrying the retainer is jour- The shaft 21 is naled in bearings carried respectively 'by the I The axes of the shafts 21 and 33 are not only parallel with each other, and at right angles to the line of feed, but they are parallel with the axis of the main actuating shaft n. plane containing the line of feed, and it moves in a direction opposed to the feed when it enters the needle thread loop.

In Figures 1 to 5 of the drawingsya single eccentric is shown on the main actuating shaft for operating both the looper and the retainer. This is accomplished in the following manner. On the outer end of the shaft 33 is an arm 34. Said arm is attached to a split collar 35 which is clamped to the shaft 33 by. a clamping screw 36. On the main actuating shaft ii is an eccentric 31. An eccentric strap 38 cooperates with this eccentric. A link 33 is pivoted at 40 to the arm 34 and is'pivoted at ll to the outer end of The looper oscillates in a vertical.

vided with a split collar which surrounds the shaft, and a clamping screw 43 rigidly attaches said arm to the shaft 21. This arm 42 is pivoted at M to the eccentric.strap 38 intermediate the ends thereof. As the main actuating shaft rotates, it will move the eccentric strap ll endwise, and it will also oscillate said eccentric strap about the pivoted connection 44 with the arm 42. The endwise movement of the eccentric strap will oscillate the shaft 21 carrying the loopers, and the turning'movement of the strap about the pin 44 as a fulcrum will, through the link 39, oscillate the shaft 33. An endwise movement of the eccentric strap will oscillate this link 39, and this will slightly modify the path of travel of the retainer, particularlyas this link does not move equally toopposite sides of the line at right angles to a line passing through the center of, the shaft l I and the pivot point M. The path of the retainer is an oval path with the upward travel thereof slightly flat.

The principal movement 'given to the retainer is obtained through the lateral movement of the eccentric strap. Thus it'is that the looper and the retainer are given their back and forth movements in proper timing to pass a looper thread loop through the needle loop for locking the same, and to spread and hold the looper thread loopfor the needle to enter on its next descent. y

Mounted on the under side of the throat plate is a spreader 46. This spreader 46 is associated with the needle 9 and retainer 32. There is a similar spreader 46a associated with the needle Ill and the retainer 32a.. .These spreaders cooperate with the retainer and the looper in the Fig. 5. The eccentric turns in the direction of the arrow, or clockwise. The looper is at the rar end of its stroke and will be moved to the forward end of its stroke by rotation of the eccentric through' 180 degrees which gives the full endwise movement to the eccentric strap. In-

reaches the forward end of its stroke. In other words, the retainer is degrees behind the looper in its movement. The looper and retainer, in Fig. 7, are shown in ,the position which they are moved to by the parts when positioned as shown in Fig. 5, that is, the looper is all the way back about to move forward, and the retainer is on its backward movement, having covered half of its path of travel. At this time, the needle is all the way down, and is about to rise to throw out its needle loop for the looper to enter. The needle is at the lower end of its stroke when the looper is at the rear end of looper has entered the thread loop and -the looper thread loop has seized by the retainer. The needle is W1 1 -its descent,

and has moved a short distance toward the fabric. The looper at this time has also started on its retracting movement. As .above noted, the looper is at the forward end of its stroke when the needle is at the upper end of its stroke.

, The notched end 32b of the retainer engages the strand of thenewly formed looper thread loop 1 the forward end of its stroke. The needle point is just entering the thread triangle formed by the strand of the looper thread loop F extending from the retainer to the previous stitch, the looper thread extending along the looper and the needle thread loop 12 on the looper. In Fig. 10, the looper has further retracted and is about to shed the needle thread loop therefrom, the retainer is on its backward movement, and. the needle is continuing its downward movement.

From the aboveit will be apparent that the retainer and the spreader cooperate with .the looper in the holding of the looper thread loop positively positioned for the point of the needle to enter said loop, and at the same time, the feed of the fabric holds the needle thread loop well back on the looper, so that the needle will, with certainty, enter the deeper thread loop in advance of the needle loop and complete the stitch.

The means for mounting the loopers and the retainers, and the construction of the spreader, as shown in Figures 12 to 14, are similar to those described above, and similar reference numerals have been applied thereto. The only difference in the construction shown in these figures, is in the means for operating the looper shaft and the retainer shaft and the timing of the looper relative to the timing of the needle and the retainer. In this form 'of the invention, the looper shaft 21 carries an arm 53 which is rigid y and adjustably clamped thereto so that it may be shifted to different set angular positions thereon as has been described in connection with the arms 34 and 42. The eccentric strap 54 is pivoted at 55 to this arm 53 andthe eccentric strap cooperates with the eccentric 56 on the main actuating shaft Ii. The shaft 33 carrying the retainers has rigidly and adiustably attached thereto an arm 51 which is pivoted at 58 to an eccentric strap 59 cooperating with an eccentric 60 on the main actuating shaft. I i.

As the main actuating shaft rotates, the eccentric straps will impart oscillations to the looper and retainer. The looper and retainer may be timed precisely as describedin connection with Figures 1 to 11, inclusive. The looper,- however, may be timed so as to be completely retracted from the needle thread loop before the point of the needle enters the looper thread loop. In Fig. 14 of the drawings, the retainer is shown at the forward end of its stroke. The looper is shown as having moved out of the needle thread loop u The looper thread 1 as clearly shown in Fig. 15, extends from the eye of. the looper through the needle thread loop, thence alongside of the spreader 46 and around the retainer 32. From the retainer, the strand of the looper thread loop extends on the other side of the spreader 46 and back through the needle thread loop n to the previous stitch. The spreader 44 iscooperating with the retainer in holding the looper thread loop well open for the needle point to enter the same. Itwill, therefore, be apparent that a stitch forming mechanism has been provided whichis very positive in its action and contributes to a high speed machine. The looper does not have any needle avoiding movement, and the thread loops formed are laid flat against the under face of the fabric. The looper and the spreader move in planes parallel with the line of feed, and therefore, the needles may be placed very close together. In Figures 1 and 2, they are shown as spaced a considerable distance from each other. In Fig. 11, however, they are shown very close to each other, and this clearly illustrates the advantage in the arrangement of the looper and spreader in a narrow gauge machine. The looper moves into the needle thread loop in a direction opposed to the direction of feed, and therefore, the feed carries the fabric away from the looper point, and this aids in the holding of the needle thread loop well back on the looper. While the looper, retainer and spreader are positively holding the looper thread positioned for the needle to enter, the feed of the fabric carries the needle loop back well out of the way of the needle, so that the triangle which the needle enters, is thus positively positioned for the needle to pass into the same with certainty. The direction of feed is indicated by the arrow in Figures 7 to 10;

As stated above, the looper shaft and the spreader shaft are mounted in a frame which is capable of being turned about the actuating shaft as a center to diiferent set positions. In Fig. 2 of the drawings, the frame arm 3| is shown as having a tapered recess 41 therein. Attached to the bed I of the machine is an upstanding member 48 on which is mounted a sleeve 49. In this sleeve 49 is mounted a bolt 50. The bolt has a tapered end adapted to fit within the recess 41. Said bolt has a reduced shank which projects through the end of the sleeve 49 and a spring 5i within the sleeve bears against a shoulder on the bolt and against the end of the sleeve and normally forces the bolt to the right as viewed in Fig. 2, so as to cause it to enter the recess 41. There is a knurled hand piece 52 on the outer end of the-bolt by which it may be retracted. The spring will cause the bolt to enter the recess, and when fully seated in the recess, the frame will be set in a fixed position relative to the bed. When the bolt is withdrawn, the frame may be lowered to the position shown in Fig. 4. This places the looper well beneath the work support so that it is made readily accessible for threading. The frame is then raised and the bolt 50 brought into engagement with the recess 41 and this will lock the frame in its raised position, and thus hold the looper and spreader in proper position to cooperate with the needle, and with each other in the stitch formation.

It is obvious that changes may be made in the details of construction and the arrangement of the'parts without departing from the spirit of the invention as set forth in the appended claims.

Having thus described the invention, what we claim as new and desire to secure by Letters- Patent, is-

1. The combination of a work support, a feeding mechanism, a needle, a thread carrying loop-- er, a loop retainer adapted to engage and retain the looper thread loop, and a stationary spreader adapted to engage thestrand of the looper thread loop between the retainer and the previous stitch for positively positioning the looper thread loop for the needle to enter.

2. The combination of a work support, a feeding mechanism, a needle, a thread carying'looper, a loop retainer adapted to engage and retain the looper thread loop, a stationary spreader carried by the work support, said spreader having the face thereof away from the looper inclined, and said retainer being positioned so as to carry the strand of the looper thread extending from the retainer to the previous stitch into engagement with said inclined face of the spreader for positively positioning the looper thread loop for the needle to enter. I

3. The combination of a work support, a feeding mechanism-a needle, a thread carrying looper movable in a plane parallel with the line of feed and in a direction opposed to the feed when entering the needle thread loop, a loop retainer movable in a plane parallel with the work support and adapted to engage and retain the looper thread loop and the stationary spreader adapted to engage the strand of looper thread loop between the retainer and, the previous stitch for positively positioning the looper thread loop for the needle to enter.

4. The combination of a work support, a feeding mechanism, a needle, a thread carrying looper mounted for movement in a plane parallel with the line of feed and in a direction opposed to the feed when entering the needle thread loop, a loop retainer movable in a plane parallel with the line of feed, a stationary spreader car ried by the work support and having the face thereof away from the looper inclined, said retainer operating to carry the strand of the looper thread loop extending from the retainer to the previous stitch into engagement with said inclined face of the spreader for positively positioning the looper thread loop for the needle to enter.

5. The combination of a work support, an actuating shaft located beneath the work support, a feeding mechanism, a. needle, a thread carrying looper, a supporting shaft therefor parallel with said actuating shaft, a retainer, a supporting shaft for said retainer parallel with said actuating shaft, a stationary spreader cooperating with said retainer for aiding in the positioning of the looper thread loop for the needle to enter, and means operated by said actuating shaft for oscillating the looper supporting shaft and the retainer supporting shaft.

6. The combination of a work support, an actuating shaft located beneath the work support, a feeding mechanism, a needle, a thread carrying looper, a supporting shaft therefor parallel with said actuating shaft, a retainer, a supporting shaft for said retainer parallel with said actuating shaft, a stationary spreader cooperating with said retainer for aiding in the positioning of the looper thread loop for the needle to enter, an eccentric carried by said actuating shaft, an eccentric strap cooperating with said eccentric, means for connecting said eccentric strap to said looper supporting shaft whereby the endwise movements of said eccentric strap will oscillate said supporting shaft, and means for connecting said eccentric strap to said retainer supporting shaft whereby lateral movements of the eccenan eccentric on said actuating shaft, an ec'centric strap cooperating with said'eccentric, an arm on said looper supporting shaft, said arm having a pivotal connection with said eccentric strap intermediate its ends whereby the endwise movements of said eccentric strap will oscillate the looper, said retainer shaft having an arm projecting therefrom, and a link connecting said arm to the outer end of said eccentric strap whereby the lateral movements imparted to the eccentric strap about the pivotal connection of the arm on the looper supporting shaft will impart oscillations to the retainer shaft.

8. The combination of a work support, an actuating shaft, a feeding mechanism, a needle, a thread carrying looper, a supporting shaft carrying the looper disposed parallel with the actuating shaft, a frame mounted for shiftable connection about the axis of said actuating shaft on which said looper shaft is supported for oscillation, means operated by said actuating shaft for oscillating said looper supporting shaft, and means for releasably holding said frame in a set position for positioning the looper in cooperative relation to the needle, said frame when released from its holding means being shiftable to a position to render the looper accessible for threading.

9. The combination of a work support, an actuating shaft, a feeding mechanism, a needle, a thread carrying looper, a supporting shaft carrying the looper disposed parallel with the actuating shaft, a loop retainer, a shaft supporting said loop retainer disposed parallel with the actuating shaft, a frame mounted for shiftable movement about the axis of said actuating shaft, said looper supporting shaft and said retainer supporting shaft being mounted for oscillation in said frame, means operated by said actuating shaft for imparting oscillations to the looper supporting shaft and said retainer shaft, and

means for releasably holding said frame in a set position for positioning the looper and retainer in cooperative relation to theneedle, said frame when released from its holding means being shiftable to a position to render thelooper accessible for threading.

10. The combination of a work support, a feeding mechanism, a needle a thread manipulating member cooperating with said needle, a shaft, a carrier mounted on said shaft, said thread manipulating member having a shank extending through said carrier and adapted to bemoved laterally into contact with said shaft, clamping means for engaging the shank for clamping said shank and carrier to the shaft and permitting said carrier to be angularly adjusted on the shaft and the shank of the thread manipulating member to be endwise adjustable'in said carrier.

11. The combination of a work support, a feeding mechanism, a plurality of needles, a looper cooperating with each needle, a shaft on which said loopers are mounted, a carrier for each looper mounted for the shaft and endwise of the shaft, said looper having a shank extending through the carrier and adapted to be moved laterally into contact with the shaft,'a clamping means mounted on the carrier and adapted to engage said shank and clamp the same against the shaft for holding the carrier and the looper associated therewith in a set position on the shaft.

12. The combination of a work support, a. feeding mechanism, a plurality of needles, a looper cooperating with each needle, a shaft on which said loopers are mounted, a carrier for each looper mounted for adjustment angularly of the shaft and endwise of the shaft, said looper having a shank extending through the carrier and adapted to be moved laterally into contact with adjustment angularly of the shaft, a clamping means mounted on the carrier and adapted to engage said shank and clamp the same against the shaft for holding the carrier and the looper associated therewith in a set position on the shaft, a retainer associ- .tending through the carrier and adapted to be moved into clamping engagement with the shaft with which it is associated, and clamping means on the carrier and adapted to clamp the retainer shank against the shaft.

13. The combination of a work support, a feeding mechanism, a needle, a thread carrying looper, a loop retainer, and a spreader, said retainer and spreader cooperating with said looper in positively positioning the looper thread loop for the needle to enter.

14. The combination of a work support, a feeding mechanism, a needle, a thread carrying looper, a loop retainer, and a spreader, said retainer and said spreader operating on the looper thread loop while the looper is in the needle thread loop for positioning said looper thread loop for the needle to enter on its next descent.

15. The combination of a work support, a feeding mechanism, a needle, a thread carrying looper mounted for oscillation in a plane parallel with the line of feed and movable into the needle thread loop in a direction opposed to the feed, a loop retainer located in front of the needle and adapted to enter the needle thread loop, and a spreader disposed between the loop retainer and the needle and cooperating with the retainer for opening the looper thread loop for the needle to enter.

16. The combination of a work support, a feeding mechanism, a needle, a thread carrying looper mounted for oscillation in a plane parallel with the line of feed and movable into the needle thread loop in a direction opposed to the feed, a retainer located in advance of the needle and adapted to enter the looper thread loop, said retainer being mounted for oscillation in a vertical plane parallel with the line of feed and containing the path of reciprocation of the needle, and a. spreader located between the retainer and the needle and cooperating with the retainer for opening the looper thread loop for the needle to enter. I

ALBERT S. RIVIERE. HAROLD J. LE VESCONTE. HANS HACKLANDER. 

